A generator converts mechanical energy to electrical energy. An Alternating Current (AC) generator is comprised of two primary components: a rotor and a stator. The rotor is made up of electrically conductive coils that form a rotor winding. The stator is also made up of coils that form a stator winding. Mechanical energy turns the rotor relative to the stator while a field current is passed through the rotor winding to induce a voltage on the stator winding. The induced power in the stator winding is supplied to loads that are powered by the generator. The electrical energy produced by the generator should be equal to the amount of electrical energy consumed by the loads.
Power plants often have multiple generators to supply power for various loads of a community. Examples of loads within the community may include lighting, heating, cooling, appliances, and other machinery. The community's demand for power often fluctuates throughout the day and based on the time of year. During a daily cycle the demand may peak during the evening hours and fall at night when most people are asleep. The yearly demand cycle for power may peak during summer months due to the increased use of air conditioning. The power plant needs to be able to increase and decrease the amount of energy supplied. The power plant may shut down one or more generators, thereby reducing the amount of electrical energy produced. During periods when the community has an increased demand, the power plant may restart generators that have been off-line to supply the additional energy demand of the community.
In addition to shutting down generators to meet the current load of the community, generators must also be shut down for routine maintenance and repair. For example, some generators may need to be shut down after periods of high use to prevent overheating and destruction of the various parts of the generator. The time and costs for shutting down and starting a generator may vary depending on the type of generator and the size of the generator. For example, a large generator powered by nuclear fuel may require considerably greater cost to shut down and start compared to a smaller diesel fuel, substation generator. In addition, some generators are designed to be very efficient at their optimal running speed, but have very slow ramp-up rates and require incremental warmth-dependent startup which adds to the startup costs. Other factors that can affect shutdown time and costs may include equipment availability, for example boilers, steam turbine generators, combustion turbine, chillers, powerhouse auxiliaries, and air compressors. Other factors that may affect startup and shutdown may include the current electricity prices, generator fuel costs, and costs for ancillary components such as air and chilled water. The amount of pollutants produced by the power plant during specific periods of time may also affect the decision to shut down and start specific generators.
The complexity and huge quantity of factors can make determining the minimum operation and shutdown time a complicated process. Accordingly, an efficient and effective system and method to model and optimize the operation and shutdown time for a generator is needed. In view of the foregoing, it would be desirable to provide systems and methods that can determine, model and optimize the operation and shutdown time.